Radioimmunoassays and Enzyme-linked immunosorbant assays will be developed to detect the presence of toxins produced by the marine dinoflagellate Ptychodiscus brevis in shellfish and fish. The assays will be refined to allow the quantitation of these toxins to permit routine assay in field specimens. The toxins, name T17 and T34 will be coupled to an albumin carrier by chemical means to produce antigenic substance. Antibodies will then be raised in goats and rabbits. Once the antibodies have been produced, and the assays developed, they will be refined using shellfish and fish which have been fed the purified toxins adsorbed to food. Following successful studies in the laboratory, field specimens of fish and shellfish, collected during incidences of Florida red tide will be assayed for the presence of T17 and t34. Assay of large predator fishes such as grouper and barracuda will be included in these assays to investigate the possibility that P. brevis neurotoxins are partly responsible for outbreaks of "Ciguatera" food poisoning.